Surgical saw device and method of manufacture

ABSTRACT

A surgical saw includes a shaft, a first saw blade mounted on the shaft, a second saw blade mounted on the shaft parallel to the first saw blade, the first saw blade having a first tooth having two distal tips, and the second saw blade having a second tooth with a distal tip, the second tooth bent towards the first saw blade and the distal tip of the second tooth aligned with a centerline between the two distal tips of the first tooth.

FIELD

This disclosure relates to surgical saw devices and methods of makingsurgical saw devices for cutting bone during surgery, and in particularto surgical saw blades adapted to be operatively coupled to poweredsurgical instruments.

BACKGROUND

Powered reciprocating saws with coupled bone cutting reciprocatingsurgical saw blades are widely used in orthopedic surgery. Typically,reciprocating surgical saw blades are used to form longitudinal cuts inbone, in line with the reciprocating action of a surgical reciprocatingmotor. These surgical reciprocating motors typically operate at speedsfrom 8,000 cycles per minute to up to approximately 16,000 cycles perminute, and have a stroke or “excursion” of approximately 3 mm-6 mm. Areciprocating surgical saw blade typically includes a proximal endcoupled to the coupling member of the surgical reciprocating motor, anda distal end with a cutting means including an array of bone cuttingteeth. The dimensions of a cutting means of a reciprocating surgical sawblade typically range from 0.38 mm to 1.47 mm in thickness, from 5 mm to15 mm in height, and from 12 mm to 90 mm in length.

The cutting means of reciprocating surgical saw blades are typicallyarrayed parallel to the longitudinal axis of the reciprocating surgicalsaw blade and parallel with the reciprocating motion of the poweredsurgical saw. In some instances, the cutting means may include bonecutting teeth arrayed upon a projection perpendicular to and extendingaway from the longitudinal axis of the reciprocating surgical saw blade.In other instances, there may be more than one cutting means.

Typically, teeth arrayed along the cutting means of reciprocatingsurgical saw blades are spaced apart (pitch between the teeth) in such amanner that anywhere from 4 to 12 teeth would engage a bone within theexcursion of a single complete reciprocating cycle of the poweredsurgical saw. In other words, the distance between the teeth istypically always less than the stroke or excursion of the poweredsurgical saw. This arrangement of teeth distributes the work-load amongmore teeth, reducing the chip load placed upon any individual tooth, andmore importantly reduces the possibility of placing undue stress or heatupon the bone being cut. Further to mitigate placing undue stress orheat upon the bone being cut by reciprocating surgical saw blades, suchblades are typically quite thin with a medium or fine pitch between theteeth.

Reciprocating surgical saw blades with cutting means projectingperpendicular to and extending away from the longitudinal axis of thereciprocating surgical saw blade are often used to perform closed bonecuts wherein the kerf, the dimensions of the saw cut, created by thereciprocating surgical saw blade, is closed on all 4 sides of the bonecut, such that there is no entry slot or exit slot. As a result, insurgical applications requiring bone cuts with such closed profiles,additional stress is placed upon the bone being cut, because thereciprocating surgical saw blade runs up against a vertical wall of boneas the reciprocating surgical saw blade is fed downwardly into theclosed slot and reciprocated by advancing and retracting within theclosed slot.

Surgical applications calling for closed profile bone cutting areadditionally complicated in that the width of the kerf of the closedprofile is typically up to 6× wider than the width of the cutting meansof a typical reciprocating surgical saw blade. Perpendicular protrudingcutting blades are often used to place closed slots in bone to receive astabilizing feature on a prosthetic orthopedic implant, which iscritical to the long-term stability and success of that implant.However, simply widening the cutting means to 6× its typical width wouldplace additional undue stress on the bone being cut, to the point ofpossible fracture of the bone. As such, in surgical applications callingfor closed profile bone cutting, in order to reduce the stress placedupon the bone, reciprocating surgical saw blades with two parallelcutting means are typically used. Such a surgical saw blade 10, is shownin FIGS. 1A-1C, in accordance with the prior art. While stress beingplaced upon the bone may be reduced by using reciprocating surgical sawblades such as those of FIGS. 1A-1C, other surgical objectives may notbe obtained. As an example, if the thicknesses of the two parallelcutting means 16 and 20, as shown in FIG. 1B, are acceptable in thatthey do not place undue stress on the bone being cut, each of theparallel cutting means 16 and 20 may not be wide enough to generate akerf wide enough to receive the stabilizing feature of various implants.Also, if the thicknesses of the two parallel cutting means 16 and 20 areacceptable in that they do not place undue stress on the bone being cutand are simply spaced apart to the point that they are wide enough togenerate a kerf wide enough to receive the stabilizing feature ofvarious implants, there may be a ridge of bone left between the twoparallel cutting means 16 and 20. The resulting bone ridge is especiallydifficult to remove when performing closed profile bone cutting.

What is needed is a reciprocating surgical saw blade suitable foroperation with a surgical reciprocating motor that can perform closedprofile bone cutting. The resulting kerf cut by the reciprocatingsurgical saw blade needs to be long enough and wide enough to receivethe stabilizing features of an orthopedic implant, and the cutting meansof the reciprocating surgical saw blade needs to form the kerf withoutplacing undue stress on the bone being cut. The embodiments of thepresent disclosure answer these and other needs.

SUMMARY

In a first embodiment disclosed herein, a surgical saw comprises ashaft, a first saw blade mounted on the shaft, a second saw blademounted on the shaft parallel to the first saw blade, the first sawblade having a first tooth having two distal tips, and the second sawblade having a second tooth with a distal tip, the second tooth benttowards the first saw blade and the distal tip of the second toothaligned with a centerline between the two distal tips of the firsttooth.

In another embodiment disclosed herein, a surgical saw comprises ashaft, a first saw blade mounted on the shaft, a second saw blademounted on the shaft parallel to the first saw blade, the first sawblade having a first type tooth with a single distal tip that is benttowards the second saw blade, the first type tooth arranged in themiddle of the first saw blade and the distal tip of the first type toothaligned with a center line between two distal tips of a second typetooth having two distal tips on the second saw blade, the first sawblade having a second type tooth on each side of the middle first typetooth on the first saw blade, the second type tooth having two distaltips, the first saw blade having a first type tooth having one distaltip that is bent toward the second saw blade on a side of each secondtype tooth on the first saw blade, the second saw blade having thesecond type tooth having two distal tips arranged in the middle of thesecond saw blade, and the second saw blade having a plurality of teethon either side of the middle second type tooth, the plurality of teethalternating between a first type tooth having a single distal tip thatis bent towards the first saw blade and a third type tooth having asingle distal tip that is not bent.

In yet another embodiment disclosed herein, a surgical saw comprises afirst saw blade having a first saw body having a first thickness, asecond saw blade having a second saw body having a second thickness, ashaft having a third thickness between a first side of the shaft and asecond side of the shaft, a retainer having a slot having a width equalto the sum of the first, second and third thicknesses, wherein the firstsaw blade is mounted on the first side of the shaft and the second sawblade is mounted on the second side of the shaft, and wherein theretainer is attached to the shaft and the first and second saw bladesuch that the first saw blade and the second saw blade on the first sideand the second side of the shaft, respectively, fit within the slot onthe retainer.

In still another embodiment disclosed herein, a method of manufacturinga surgical saw comprises providing a first saw blade having a first sawbody having a first thickness and having teeth on a distal end of thefirst saw body, providing a second saw blade having a second saw bodyhaving a second thickness and having teeth on a distal end of the secondsaw body, providing a shaft having a third thickness between a firstside of the shaft and a second side of the shaft, providing a retainerhaving a slot having a width equal to the sum of the first, second andthird thicknesses, placing the first saw blade on the first side of theshaft, placing the second saw blade on the second side of the shaft,mounting the retainer on the shaft so that the first saw blade fitswithin the slot on the retainer and so that the second saw blade fitswithin the slot on the retainer with the shaft between the first andsecond saw blades, and attaching the retainer to the shaft and theretainer to the first saw blade and to the second saw blade.

In still another embodiment disclosed herein a method of forming asurgical saw comprises providing a shaft, mounting a first saw blade onthe shaft, and mounting a second saw blade on the shaft parallel to thefirst saw blade, the first saw blade having a first tooth having twodistal tips, and the second saw blade having a second tooth with adistal tip, the second tooth bent towards the first saw blade and thedistal tip of the second tooth aligned with a centerline between the twodistal tips of the first tooth.

In yet another embodiment disclosed herein a method of performingsurgery comprises using a surgical saw having a shaft, a first saw blademounted on the shaft, a second saw blade mounting on the shaft parallelto the first saw blade, wherein the first saw blade has a first toothhaving two distal tips, and the second saw blade has a second tooth witha distal tip, the second tooth bent towards the first saw blade and thedistal tip of the second tooth aligned with a centerline between the twodistal tips of the first tooth.

These and other features and advantages will become further apparentfrom the detailed description and accompanying figures that follow. Inthe figures and description, numerals indicate the various features,like numerals referring to like features throughout both the drawingsand the description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C show a side elevation view, a top view and a front view,respectively, of a surgical saw in accordance with the prior art;

FIG. 1D illustrates a method of fabricating a surgical saw in accordancewith the prior art;

FIGS. 2A-2F show a perspective view, a side elevation view, a bottomview, a rear view, a front view, and a top view, respectively, of asurgical saw in accordance with the present disclosure;

FIG. 3 shows another perspective view of a surgical saw in accordancewith the present disclosure;

FIG. 4 illustrates a method of fabricating a surgical saw in accordancewith the present disclosure;

FIGS. 5A-5G show alternate bottom views of surgical saws in accordancewith the present disclosure;

FIGS. 6A and 6B are block diagrams of a method of manufacturing asurgical saw in accordance with the present disclosure;

FIGS. 7A-7F show a perspective view, a side elevation view, a bottomview, a rear view, a front view, and a top view, respectively, ofanother surgical saw in accordance with the present disclosure;

FIG. 8 shows another perspective view of a surgical saw in accordancewith the present disclosure;

FIG. 9 is a block diagram of a method of manufacturing a surgical saw inaccordance with the present disclosure; and

FIG. 10 is a block diagram of a method of performing surgery inaccordance with the present disclosure.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toclearly describe various specific embodiments disclosed herein. Oneskilled in the art, however, will understand that the presently claimedinvention may be practiced without all of the specific details discussedbelow. In other instances, well known features have not been describedso as not to obscure the invention.

Referring now to FIGS. 1A to 1C, a surgical saw 10 is shown for use witha surgical reciprocating motor (not shown) in accordance with the priorart. FIG. 1A shows a side elevation view of the surgical saw 10, showingthe shaft 12, which is typically coupled to a surgical reciprocatingmotor, and a saw blade 16 with teeth 18 projecting perpendicular to theshaft. In this view only the teeth 22 of the parallel saw blade 20 canbe seen. The shaft 12 has a protrusion 30 with a distal end 14 extendingbetween the saw blades 16 and 20. FIG. 1B is a top view of the surgicalsaw 10, which shows the two parallel saw blades 16 and 20, having teeth18 and 22, respectively. FIG. 1C is a front view the surgical saw 10 andillustrates the two saw blades 16 and 20 projecting perpendicular fromthe shaft 12.

FIG. 1D illustrates a method of fabricating the surgical saw of FIGS.1A-1C in accordance with the prior art. First of all the shaft 12 isformed. As is evident in FIG. 1D to form the shaft 12 with protrusion 30formed with recesses 32 requires complicated cutting and milling. Toform the saw blades 16 and 20 also requires complicated cutting andmilling to form teeth 18 and 22, respectively, and to form wings 24 and26, respectively. The wings 24 and 26 of the saw blades 16 and 20,respectively, are aligned with recesses 32 and then welded to the shaft12 to complete the assembly of the surgical saw 10.

In FIG. 1C it is shown that in this prior art surgical saw 10, that thebodies 17 and 21 of the saw blades 16 and 20, respectively, are thinnerthan the teeth 18 and 22, respectively. In the prior art the teeth mayalso have the same width as the body of the saw blade. As discussedabove, the width of the teeth may be selected to form a kerf with alittle or no bone ridge between where the teeth cut the bone whenperforming closed profile bone cutting, as well as other types of cuts.However, as also discussed above, wide teeth may result in undue stressbeing placed on the bone being cut.

Referring now to FIGS. 2A to 2F, a surgical saw 40 in accordance withthe present disclosure is shown. FIG. 2A is one perspective view of thesurgical saw 40 and FIG. 3 is another perspective view of a surgical saw40 in accordance with the present disclosure, which also shows the endof the surgical saw 170 and protrusions 172 and 174 for mounting thesurgical saw 40 to a surgical reciprocating motor. Referring again toFIG. 2A, the surgical saw 40 has a shaft 42 and a retainer 44 upon whichsaw blades 45 and 46 are mounted as described further below. Theretainer 44 may be attached to a boss 50 on the shaft 42.

FIG. 2B is a side elevational view of the surgical saw blade 40 showingfurther details of the teeth on each saw blade 45 and 46. As shown inFIG. 2B, the saw blades are parallel to one another.

The saw blade 46 has three types of teeth, a first type tooth with asingle distal tip that is bent toward the parallel saw blade 45, asecond type tooth with two distal tips that is not bent, and a thirdtype tooth with a single distal tip that is not bent. The purpose of thefirst type tooth that is bent toward the parallel saw blade is to widenthe cut or kerf. The purposes of the second and third type teeth are tocreate a cutting path and to help with down feeding of the saw bladeinto the cut. On saw blade 46 the middle tooth 60 is a first type toothwith a single distal tip and is bent toward saw blade 45 by an amountdescribed below. On either side of tooth 60 are teeth 70 and 80 that aresecond type teeth that each have two distal tips 72, 74, and 82, 84,respectively, and are not bent. Teeth 70 and 80 may be described asfishtail teeth in that they have 2 distal tips. Going further away fromthe middle tooth 60, saw blade 46 has teeth 76 and 86, next to teeth 70and 80, respectively. Teeth 76 and 86 are first type teeth with only onedistal tip and are bent toward saw blade 45. Going even further awayfrom the middle tooth the saw blade may have additional third type teetheach with a single distal tip that is not bent. In one embodiment thefirst type teeth and the third type teeth may have a shape of anisosceles triangle.

Also shown in FIG. 2B are the tips of teeth on saw blade 45. In themiddle of saw blade 45 is a second type tooth 63 with two distal tips 62and 64. On either side of tooth 63 are teeth 90 and 92, which are firsttype teeth with one distal tip bent toward the parallel saw blade, whichis saw blade 46. Going further away from the middle tooth 63, saw blade45 has third type teeth 77 and 87, next to teeth 90 and 92,respectively. Teeth 77 and 87 each have one distal tip that is not bent.Going even further away from the middle tooth 63, saw blade 45 has afirst type tooth 94 and 96 next to teeth 77 and 87, respectively. Thensaw blade 45 has third type teeth next to teeth 94 and 96, respectively.

FIGS. 2C-2F show a bottom view, a rear view, a front view, and a topview, respectively, of a surgical saw 40 in accordance with the presentdisclosure. FIGS. 2C-2E show that the first type teeth, including teeth60, 76 and 86 on saw blade 46 are bent toward saw blade 45, and firsttype teeth 90, 92, 94 and 96 on saw blade 45 are bent toward saw blade46. As shown in FIGS. 2D and 2E, the saw blade 46 has a saw body 43which has a thickness and the teeth on saw blade 46, such as teeth 60,70, 76, 80 and 86, are on a distal end of the saw body 43. In oneembodiment the first type teeth, such as teeth 60, 76 and 86 on sawblade 46 are bent towards saw blade 45 by an amount not exceeding 150%of the thickness of the saw body 43. Similarly, the saw blade 45 has asaw body 47 which has a thickness and the teeth on saw blade 45, such asteeth 63, 90, 77, 94, 92, 87, and 96, are on a distal end of the sawbody 47. The first type teeth, such as teeth 90, 92, 94 and 96 on thesaw blade 45 are bent towards saw blade 46 by an amount not exceeding150% of the thickness of the saw body 47. In another embodiment thedistal tip of the bent middle tooth 60 on saw blade 46 has a height thatis less that the height of the two distal tips of tooth 63 on saw blade45. In another embodiment the distal tip of the bent middle tooth 60 onsaw blade 46 is aligned such that the distal tip of tooth 60 is alignedwith a centerline between the two distal tips 62 and 64 on second typetooth 63, as is best shown in FIG. 2B.

The assembly of the surgical saw 40 is best understood in relation toFIG. 4, which shows a disassembled surgical saw. As shown in FIG. 4,tangs 110 and 112 are on the proximal end of saw blade 46, and tangs 114and 116 are on the proximal end of saw blade 45. The shaft 42, as shownin FIG. 4, has recesses 52 and 54, which result in a thickness at areas53 and 55. A boss 50 is also formed on shaft 42 between areas 53 and 55.FIG. 4 also shows retainer 44, which has slots 100, 102 and 104. Asshown in FIG. 2F, when assembled the boss 50, which has a width, is fitinto slot 100, which has a corresponding width. Also tang 110 on sawblade 46, area 53, and tang 114 on saw blade 45 are fit into slot 102,which has a width that is approximately the sum of the thicknesses oftang 110, area 53, and tang 114. Similarly, tang 112 on saw blade 46,area 55, and tang 116 on saw blade 45 are fit into slot 104, which has awidth that is approximately the sum of the thicknesses of tang 112, area55, and tang 116. Once the assembly of the boss 50 into slot 100, theassembly of tang 110 on saw blade 46, area 53, and tang 114 on saw blade45 into slot 102, and the assembly of tang 112 on saw blade 46, area 55,and tang 116 on saw blade 45 into slot 104 are complete, simpleattachment methods may be used to fasten saw blades 45 and 46, retainer44, and shaft 42 together. The result is a surgical saw that is easierto fabricate and assemble than the prior art assembly as discussed abovewith reference to FIG. 1D.

FIGS. 5A-5G show alternate bottom views of surgical saws formed inaccordance with the present disclosure. FIG. 5A shows an alternate boss130, which has a diamond form. In this embodiment the slot 100 has amatching diamond shape. FIG. 5B shows another boss 132, which has acircular form. In this embodiment the slot 100 has a matching circularshape. FIG. 5C shows another boss 134, which has a triangular form. Inthis embodiment the slot 100 has a matching triangular shape. FIG. 5Dshows yet another boss 136 design, which in this design includes tworectangular forms. In this embodiment the slot 100 would be tworectangular matching slots. FIG. 5E shows yet another boss 138 design,which in this design has a rectangular form, but which is narrower thanslot 100. The saw blades 45 and 46 each have an additional tang 111 and115, respectively, which fit on either side of the boss 138 and fit intorectangular slot 100. FIG. 5F shows yet another boss 140, which in thisdesign also has a rectangular form that is narrower than slot 100. Thesaw blades 45 and 46 each have one tang 150 and 152, respectively, whichfit on either side of the boss 140, but are longer than the boss 140 andthe slot 100 includes linear slits into which the longer tangs 150 and152 fit. This design has the advantage that each saw blade needs to onlyhave one tang, albeit a longer tang in order to ensure that the tangwhen welded to the retainer 44 and the shaft 42 is securely fastened.FIG. 5G shows yet another boss 142, which in this design also has arectangular form that is narrower than slot 100. The saw blades 45 and46 each have one tang 150 and 152, respectively, which fit on eitherside of the boss 142. In this embodiment, the boss 142 and the tangs 150and 152 each have the same length, so the slot 100 may be rectangular.Similar to the embodiment of FIG. 5F, each of the saw blades 45 and 46need only have one tang in the embodiment of FIG. 5G.

In another embodiment, saw blades 45 and 46 have no tangs but ratherjust have proximal ends 150 and 152 respectively, as shown in FIGS. 5Fand 5G, that fit into the linear slits on FIG. 5F or on either side ofboss 142 as shown in FIG. 5G.

FIGS. 6A and 6B are block diagrams of a method of manufacturing asurgical saw in accordance with the present disclosure. The methodincludes step 400 of providing a first saw blade 45 having a first sawbody 47 having a first thickness and having teeth on a distal end of thefirst saw body 47, step 402 of providing a second saw blade 46 having asecond saw body 43 having a second thickness and having teeth on adistal end of the second saw body 43, step 404 of providing a shafthaving a third thickness between a first side of the shaft 52 and asecond side of the shaft 54, step 406 of providing a retainer 44 havinga slot 102 having a width equal to the sum of the first, second andthird thicknesses, step 408 of placing the first saw blade 45 on thesecond side 54 of the shaft 42, step 410 of placing the second saw blade46 on the first side 52 of the shaft 42, step 412 of mounting theretainer 44 on the shaft 42 so that the first saw blade 45 fits withinthe slot 100 on the retainer 44 and so that the second saw blade 46 fitswithin the slot 100 on the retainer 44 with the shaft 42 between thefirst and second saw blades, and step 414 of attaching the retainer 44to the shaft 42 and the retainer 44 to the first saw blade and to thesecond saw blade.

The method of attaching may include welding, laser welding, brazing,gluing and any other attaching methods well known in the art. The methodmay also include steps of attaching the tangs on the saw blades to theretainer and the shaft.

Referring now to FIGS. 7A to 7F, a surgical saw 540 in accordance withthe present disclosure is shown. FIG. 7A is a perspective view of thesurgical saw 540. The surgical saw 540 has a shaft 542 which can beattached to a motor. FIG. 7B is a side elevational view of the surgicalsaw blade 540 showing further details of the teeth on each saw blade 545and 546. As shown in FIG. 2B, the saw blades are parallel to oneanother.

The saw blade 546 has three types of teeth that are arranged in the sameway as the teeth on saw blade 46 described above. A first type toothwith a single distal tip that is bent toward the parallel saw blade 545,a second type tooth with two distal tips that is not bent, and a thirdtype tooth with a single distal tip that is not bent. The purpose of thefirst type tooth that is bent toward the parallel saw blade is to widenthe cut or kerf. The purposes of the second and third type teeth are tocreate a cutting path and to help with down feeding of the saw bladeinto the cut. On saw blade 546 the middle tooth 60 is a first type toothwith a single distal tip and is bent toward saw blade 545 by an amountdescribed below. On either side of tooth 60 are teeth 70 and 80, asshown in FIG. 8, that are second type teeth that each have two distaltips and are not bent. Teeth 70 and 80 may be described as fishtailteeth in that they have 2 distal tips. Moving further away from themiddle tooth the saw blade 546 has another first type tooth and then twothird type teeth. In one embodiment the first type teeth and the thirdtype teeth may have a shape of an isosceles triangle.

Also shown in FIG. 7B and FIG. 8 are the tips of teeth on saw blade 545that has three types of teeth that are arranged in the same way as theteeth on saw blade 45 described above. In the middle of saw blade 545 isa second type tooth 63 with two distal tips. On either side of tooth 63are teeth 90 and 92, which are first type teeth with one distal tip benttoward the parallel saw blade, which is saw blade 546. Going furtheraway from the middle tooth 63, saw blade 45 has third type teeth whichhave a single distal tip that is not bent next to teeth 90 and 92,respectively. Going even further away from the middle tooth 63, sawblade 545 has first type teeth and then saw blade 45 has third typeteeth, in the same manner as saw blade 45 described above.

FIGS. 7C-7F show a bottom view, a rear view, a front view, and a topview, respectively, of surgical saw 540 in accordance with the presentdisclosure. FIGS. 7C-7E show that the first type teeth on saw blade 546are bent toward saw blade 545, and first type teeth on saw blade 545 arebent toward saw blade 546. As shown in FIGS. 7D and 7E, the saw blade546 has a saw body 543 which has a thickness. In one embodiment thefirst type teeth on saw blade 546 are bent towards saw blade 545 by anamount not exceeding 150% of the thickness of the saw body 543.Similarly, the saw blade 545 has a saw body 547 which has a thicknessand the first type teeth on the saw blade 545 are bent towards saw blade546 by an amount not exceeding 150% of the thickness of the saw body547. In another embodiment the distal tip of the bent middle tooth 60 onsaw blade 546 has a height that is less that the height of the twodistal tips of tooth 63 on saw blade 545. In another embodiment thedistal tip of the bent middle tooth 60 on saw blade 546 is aligned suchthat the distal tip of tooth 60 is aligned with a centerline between thetwo distal tips on second type tooth 63, as is best shown in FIG. 7B.

The assembly of the surgical saw 540 is best understood in relation toFIG. 8, which shows a disassembled surgical saw. As shown in FIG. 8, theshaft 542 has recesses 552 and 554, which extend to recesses 553 and555, respectively. These recesses reduce the thickness of shaft 542 andprovide mounting surfaces for saw blades 545 and 546. As shown in FIG. 8the shaft 542 also has protrusions 530 and 532. The body 543 of sawblade 546 and the body 547 of saw blade 545 have a length which fitsbetween the protrusions 530 and 532 when the surgical saw is assembled.The protrusions 530 and 532 extend outward from the shaft a distancethat is approximately the thickness of the saw blade bodies 543 and 547.Saw blade 545 includes the saw body 547 with teeth on the distal end ofthe saw body 547, as discussed above, and the saw body 547 is integralwith a stop guide 534 that fits along recess 554 and 553. Similarly, sawblade 546 includes the saw body 543 with teeth on the distal end of thesaw body 543, as discussed above, and the saw body 543 is integral witha stop guide 536 that fits along recess 552 and 555.

When the saw blades 545 and 546 are fit within the recesses on shaft542, simple attachment methods may be used to fasten saw blades 545 and546 to shaft 542. The result is a surgical saw that is less costly tofabricate and assemble than the prior art assembly as discussed abovewith reference to FIG. 1D.

FIG. 9 is a block diagram of a method of manufacturing a surgical saw inaccordance with the present disclosure and steps 600, 602 and 604 are inaccordance with the above description of the surgical saw.

FIG. 10 is a block diagram of a method of performing surgery inaccordance with the present disclosure and step 610 is using a surgicalsaw in accordance with the above description in surgery.

Having now described the invention in accordance with the requirementsof the patent statutes, those skilled in this art will understand how tomake changes and modifications to the present invention to meet theirspecific requirements or conditions. Such changes and modifications maybe made without departing from the scope and spirit of the invention asdisclosed herein.

The foregoing Detailed Description of exemplary and preferredembodiments is presented for purposes of illustration and disclosure inaccordance with the requirements of the law. It is not intended to beexhaustive nor to limit the invention to the precise form(s) described,but only to enable others skilled in the art to understand how theinvention may be suited for a particular use or implementation. Thepossibility of modifications and variations will be apparent topractitioners skilled in the art. No limitation is intended by thedescription of exemplary embodiments which may have included tolerances,feature dimensions, specific operating conditions, engineeringspecifications, or the like, and which may vary between implementationsor with changes to the state of the art, and no limitation should beimplied therefrom. Applicant has made this disclosure with respect tothe current state of the art, but also contemplates advancements andthat adaptations in the future may take into consideration of thoseadvancements, namely in accordance with the then current state of theart. It is intended that the scope of the invention be defined by theClaims as written and equivalents as applicable. Reference to a claimelement in the singular is not intended to mean “one and only one”unless explicitly so stated. Moreover, no element, component, nor methodor process step in this disclosure is intended to be dedicated to thepublic regardless of whether the element, component, or step isexplicitly recited in the Claims. No claim element herein is to beconstrued under the provisions of 35 U.S.C. Sec. 112, sixth paragraph,unless the element is expressly recited using the phrase “means for . .. ” and no method or process step herein is to be construed under thoseprovisions unless the step, or steps, are expressly recited using thephrase “comprising the step(s) of . . . .”

1. A surgical saw comprising: a shaft; a first saw blade mounted on theshaft; a second saw blade mounted on the shaft parallel to the first sawblade; the first saw blade having a first tooth having two distal tips;and the second saw blade having a second tooth with a distal tip, thesecond tooth bent towards the first saw blade and the distal tip of thesecond tooth aligned with a centerline between the two distal tips ofthe first tooth.
 2. The surgical saw of claim 1 wherein the first toothis symmetric about the center line between the two distal tips of thefirst tooth.
 3. The surgical saw of claim 1 wherein the second tooth hasa shape of an isosceles triangle.
 4. The surgical saw of claim 1 whereinthe second saw blade comprises: a saw body having a thickness; whereinthe second tooth is on a distal end of the saw body and bent towards thefirst saw blade by an amount not exceeding 150% of the thickness of thesaw body.
 5. The surgical saw of claim 1 wherein the distal tip of thebent second tooth has less height than the two distal tips of the firsttooth.
 6. The surgical saw of claim 1 wherein: the first saw bladefurther comprises: a third tooth having a distal tip, the third toothbent towards the second saw blade and on one side of the first tooth;and a fourth tooth having a distal tip, the fourth tooth bent towardsthe second saw blade and on a second side of the first tooth; and thesecond saw blade further comprises: a fifth tooth having two distal tipswith a centerline between the two distal tips of the fifth tooth alignedwith the distal tip of the third tooth; and a sixth tooth having twodistal tips with a centerline between the two distal tips of the sixthtooth aligned with the distal tip of the fourth tooth.
 7. The surgicalsaw of claim 6 wherein the third and fourth teeth each have a shape ofan isosceles triangle.
 8. The surgical saw of claim 6 wherein the firstsaw blade comprises: a saw body having a thickness; wherein the thirdand fourth teeth are each on a distal end of the saw body and benttowards the second saw blade by an amount not exceeding 150% ofthickness of the saw body.
 9. The surgical saw of claim 1 furthercomprising: a retainer having a slot; wherein: the first saw blade has afirst saw body having a first thickness; the second saw blade having asecond saw body having a second thickness; the shaft has a thicknessbetween a first side of the shaft and a second side of the shaft; andthe slot has a width equal to the sum of the first, second and thirdthicknesses; the first saw blade is mounted on the first side of theshaft and the second saw blade is mounted on the second side of theshaft; and the retainer is attached to the shaft and the first andsecond saw blade such that the first saw blade and the second saw bladeon the first side and the second side of the shaft, respectively, fitwithin the slot on the retainer.
 10. The surgical saw of claim 9wherein: the shaft further comprises a boss; the retainer has a secondslot having a thickness equal to the third thickness of the shaft; andthe boss fits within the second slot and is attached to the shaft. 11.The surgical saw of claim 10 wherein the boss has a shape selected froma group comprising a rectangular shape, a diamond shape, a circularshape, and a triangular shape.
 12. The surgical saw of claim 9 wherein:the first saw blade comprises a tang on the proximal end of the firstsaw blade; and the second saw blade comprises a tang on the proximal endof the second saw blade; wherein the retainer is attached to the shaftand the first and second saw blade such that the tang on the first sawblade and the tang on the second saw blade are mounted on the first sideand the second side of the shaft, respectively, and fit within the sloton the retainer.
 13. The surgical saw of claim 12 wherein: the first sawblade has a second tang; the second saw blade has a second tang; and theretainer has a second slot having a width equal to the sum of the first,second and third thicknesses; wherein the retainer is attached to theshaft and the first and second saw blade such that the second tang ofthe first saw blade and the second tang of the second saw blade on thefirst side and the second side of the shaft, respectively, fit withinthe slot on the retainer.
 14. The surgical saw of claim 1 wherein: thefirst saw blade has a first stop guide on a proximal end; the second sawblade has a second stop guide on a proximal end; the shaft has a firstrecess on a first side of the shaft and a second recess on a second sideof the shaft; and the first stop guide is mounted within the firstrecess and the second saw blade is mounted within the second recess. 15.The surgical saw of claim 14 wherein: the first saw blade has a firstsaw body having a length; the second saw blade has a second saw bodyhaving the length; the shaft has a first and a second protrusionseparated by the length; and the first saw body and the second saw bodyare mounted between the first and the second protrusion.
 16. Thesurgical saw of claim 14 wherein: the first stop guide and the first sawbody are integral; and the second stop guide and the second saw body areintegral.
 17. A surgical saw comprising: a shaft; a first saw blademounted on the shaft; a second saw blade mounted on the shaft parallelto the first saw blade; the first saw blade having a first type toothwith a single distal tip that is bent towards the second saw blade, thefirst type tooth arranged in the middle of the first saw blade and thedistal tip of the first type tooth aligned with a center line betweentwo distal tips of a second type tooth having two distal tips on thesecond saw blade; the first saw blade having a second type tooth on eachside of the middle first type tooth on the first saw blade, the secondtype tooth having two distal tips; the first saw blade having a firsttype tooth having one distal tip that is bent toward the second sawblade on a side of each second type tooth on the first saw blade; thesecond saw blade having the second type tooth having two distal tipsarranged in the middle of the second saw blade; and the second saw bladehaving a plurality of teeth on either side of the middle second typetooth, the plurality of teeth alternating between a first type toothhaving a single distal tip that is bent towards the first saw blade anda third type tooth having a single distal tip that is not bent.
 18. Thesurgical saw of claim 17 wherein the middle second type tooth on thesecond saw blade is symmetric about the center line between the twodistal tips of the middle second type tooth.
 19. The surgical saw ofclaim 17 wherein each first type tooth and each third type tooth has ashape of an isosceles triangle.
 20. The surgical saw of claim 17 whereinthe first saw blade further comprises: a saw body having a thickness;wherein each first type tooth is on a distal end of the saw body andbent towards the second saw blade by an amount not exceeding 150% of thethickness of the saw body.
 21. The surgical saw of claim 17 wherein thesecond saw blade comprises: a saw body having a thickness; wherein eachfirst type tooth is on a distal end of the saw body and bent towards thefirst saw blade by an amount not exceeding 150% of the thickness of thesaw body.
 22. The surgical saw of claim 17 wherein the distal tip of themiddle first type tooth on the first saw blade has less height than thetwo distal tips of the middle second type tooth on the second saw blade.23. The surgical saw of claim 17 wherein the first saw blade furthercomprises third type teeth each having one distal tip that is not bent.24. A surgical saw comprising: a first saw blade having a first saw bodyhaving a first thickness; a second saw blade having a second saw bodyhaving a second thickness; a shaft having a third thickness between afirst side of the shaft and a second side of the shaft; and a retainerhaving a slot having a width equal to the sum of the first, second andthird thicknesses; wherein the first saw blade is mounted on the firstside of the shaft and the second saw blade is mounted on the second sideof the shaft; and wherein the retainer is attached to the shaft and thefirst and second saw blade such that the first saw blade and the secondsaw blade on the first side and the second side of the shaft,respectively, fit within the slot on the retainer.
 25. The surgical sawof claim 24 wherein: the shaft further comprises a boss; the retainerhas a second slot having a thickness equal to the third thickness of theshaft; and the boss fits within the second slot and is attached to theshaft.
 26. The surgical saw of claim 25 wherein the boss has a shapeselected from a group comprising a rectangular shape, a diamond shape, acircular shape, and a triangular shape.
 27. The surgical saw of claim 24wherein: the first saw blade comprises a tang on the proximal end of thefirst saw blade; and the second saw blade comprises a tang on theproximal end of the second saw blade; wherein the retainer is attachedto the shaft and the first and second saw blade such that the tang onthe first saw blade and the tang on the second saw blade are mounted onthe first side and the second side of the shaft, respectively, and fitwithin the slot on the retainer.
 28. The surgical saw of claim 27wherein: the first saw blade has a second tang; the second saw blade hasa second tang; and the retainer has a second slot having a width equalto the sum of the first, second and third thicknesses; wherein theretainer is attached to the shaft and the first and second saw bladesuch that the second tang of the first saw blade and the second tang ofthe second saw blade on the first side and the second side of the shaft,respectively, fit within the slot on the retainer.
 29. A method ofmanufacturing a surgical saw comprising: providing a first saw bladehaving a first saw body having a first thickness and having teeth on adistal end of the first saw body; providing a second saw blade having asecond saw body having a second thickness and having teeth on a distalend of the second saw body; providing a shaft having a third thicknessbetween a first side of the shaft and a second side of the shaft;providing a retainer having a slot having a width equal to the sum ofthe first, second and third thicknesses; placing the first saw blade onthe first side of the shaft; placing the second saw blade on the secondside of the shaft; mounting the retainer on the shaft so that the firstsaw blade fits within the slot on the retainer and so that the secondsaw blade fits within the slot on the retainer with the shaft betweenthe first and second saw blades; and attaching the retainer to the shaftand the retainer to the first saw blade and to the second saw blade. 30.The method of claim 29 further comprising providing the shaft with afirst recess on the first side of the shaft and a second recess on thesecond side of the shaft.
 31. The method of claim 30 wherein: the firstrecess has a depth equal to the first thickness of the first saw blade;and the second recess has a depth equal to the second thickness of thesecond saw blade.
 32. The method of claim 30 wherein providing the shaftwith the first recess on the first side of the shaft and the secondrecess on the second side of the shaft comprises milling or grinding.33. The method of claim 29 wherein the step of attaching compriseswelding, brazing or gluing.
 34. A method of forming a surgical sawcomprising: providing a shaft; mounting a first saw blade on the shaft;and mounting a second saw blade on the shaft parallel to the first sawblade; the first saw blade having a first tooth having two distal tips;and the second saw blade having a second tooth with a distal tip, thesecond tooth bent towards the first saw blade and the distal tip of thesecond tooth aligned with a centerline between the two distal tips ofthe first tooth.
 35. A method of performing surgery, the methodcomprising: using a surgical saw having a shaft, a first saw blademounted on the shaft, a second saw blade mounted on the shaft parallelto the first saw blade, wherein the first saw blade has a first toothhaving two distal tips, and the second saw blade has a second tooth witha distal tip, the second tooth bent towards the first saw blade and thedistal tip of the second tooth aligned with a centerline between the twodistal tips of the first tooth.